1. Field of the Invention
The present invention relates to a zinc oxide sulfide selenide (hereinafter referred to as ZnOSSe) compound semiconductor, to an integrated circuit having the ZnOSSe compound semiconductor mounted thereon and to a method of manufacturing the same. More particularly, the present invention relates to a light-emitting device, a switching device and an integrated circuit that use a silicon substrate that utilizes lattice matching of the ZnOSSe compound semiconductor and a Si semiconductor, and to a method of manufacturing these devices.
2. Description of the Prior Art
Considerable research has been conducted into growing GaAs on silicon substrates. However, even if AlGaAs should be used as the GaAs-based optical semiconductor, in terms of the principle at work, it is not possible to fabricate a light-emitting device having a wavelength shorter than that of red light. JP-A HEI 9-219563 describes an invention that successfully accomplishes lattice matching with the GaAs substrate by utilizing a large bandgap bowing parameter. GaInNAs and InNPAs have a large bandgap bowing parameter, which the invention applies to a mid-infrared light-emitting device. However, because it is a group III-V semiconductor that is being used, it is not possible to manufacture a light-emitting device that covers the visible-light spectrum.
It has been considered that the only semiconductors having a lattice that matches silicon are GaP, AlP and ultraviolet-region ZnS, which are indirect transition type semiconductors not suitable for optical applications.
An object of the present invention is to provide a light-emitting device that provides lattice matching with silicon and can provide a wide range of emission wavelengths, from infrared and visible light to ultraviolet, an integrated circuit using the device, and a method of manufacturing the same.
Another object is to provide a switching device that is lattice-matched to the silicon substrate and only operates when it receives light within a set wavelength that includes infrared, visible and ultraviolet light.
To attain the above object, the present invention provides a light-emitting device comprising: a silicon substrate, a ZnOSSe layer bonded to the silicon substrate that is lattice-matched to the silicon substrate, and a separate confinement heterostructure (SCH) light-emitting layer that is provided on the ZnOSSe layer and comprises an active layer, a lower clad layer and an upper clad layer. The SCH light-emitting layer of the light-emitting device can have the active layer formed of ZnOSSe and the upper and lower clad layers formed of ZnMgOSSe.
The above object is also attained by a switching device comprising: a silicon substrate, a ZnOSSe layer bonded to the silicon substrate that is lattice-matched to the silicon substrate, and an electrode provided on the upper surface of the ZnOSSe layer.
The above object is also attained by an integrated circuit comprising: a silicon substrate, a ZnOSSe layer provided on the silicon substrate that is lattice-matched to the silicon substrate, and an SCH light-emitting layer that is provided on the ZnOSSe layer and comprises an active layer, a lower clad layer and an upper clad layer. The SCH light-emitting layer of the integrated circuit can have the active layer formed of ZnOSSe and the upper and lower clad layers formed of ZnMgOSSe.
The above object is also attained by a method of manufacturing a light-emitting device, comprising: forming a lattice-matched ZnOSSe layer on a silicon substrate under an ultrahigh vacuum while adjusting a composition ratio of the oxygen, selenium and sulfur of the ZnOSSe layer to change a device emission wavelength within a range that includes infrared, visible and ultraviolet light without lattice mismatch; and forming on the ZnOSSe layer a light-emitting layer that comprises an active layer, a lower clad layer and an upper clad layer. A molecular beam epitaxy (MBE) method can be used to form the ZnOSSe layer on the silicon substrate. The light-emitting layer can have the active layer formed of ZnOSSe and the upper and lower clad layers formed of ZnMgOSSe while controlling the composition ratio of the zinc, magnesium, oxygen and sulfur of the ZnMgOSSe upper and lower clad layers to lower the threshold current.
The above object is also attained by a method of manufacturing an integrated circuit, comprising: forming a lattice-matched ZnOSSe layer on a silicon substrate under an ultrahigh vacuum while adjusting a composition ratio of the oxygen, selenium and sulfur of the ZnOSSe layer to change a device emission wavelength within the infrared range without lattice mismatch; and forming on the ZnOSSe layer a light-emitting layer that comprises an active layer, a lower clad layer and an upper clad layer. An MBE method can be used to form the ZnOSSe layer on the silicon substrate.
As described in the foregoing, the ZnOSSe layer of the present invention can be lattice-matched to the silicon substrate, enabling it to be formed on a silicon substrate together with a conventional semiconductor device to thereby constitute an integrated circuit. Also, by modifying the component ratios of the oxygen, selenium and sulfur of the ZnOSSe layer, the device emission wavelength can be changed within a range that includes infrared, visible and ultraviolet light.
Further features of the invention, its nature and various advantages will be more apparent from the accompanying drawings and following detailed description of the invention.